Green Trees addon - Wolfenstein: Enemy Territory

Based on Return to Castle Wolfenstein's engine, Enemy Territory started as an additional single-player campaign, but quickly evolved into a massive on-line shooter in minds of creators. The final product is a multiplayer-only, tactical and teamplay shooter. Pick your class (Soldier, medic, engineer, covert operations or field operations) and cover your teammates, heal them, build machinegun nests, bridges or deploy landmines, request airstrikes or artillery support, steal your enemy's uniform, and finally give your comrades ammo. In order to be successful, cooperative team playing is required.